Seizures in children with low-grade tumors: outcome after tumor resection and risk factors for uncontrolled seizures.

OBJECT: The goals of this study were to define the incidence of seizures in children with low-grade tumors, study seizure outcome after lesionectomy in these children, and identify risk factors for poor seizure outcome.
METHODS: The authors performed a retrospective chart review of children who harbored low-grade brain tumors, experienced seizures, and were treated in a single institution. Statistical analyses included step-wise as well as single-variable binary logistic regression analyses. Fifty-five children (20%) with seizures were identified in a cohort of 280 children with low-grade tumors. Of these 55 children, 35 harbored cortical cerebral tumors and 20 had noncortical lesions, including six whose tumors were in the posterior fossa. Seizures were defined as controlled if there was no seizure in the 12 months preceding the last clinic visit. All cortical tumors were treated by lesionectomy as an initial procedure. Of the 27 children with cortical tumors whose seizures began before tumor diagnosis, 23 had complete resection and 52% of these 23 experienced no further seizures after surgery. Seizures are presently controlled in 84% of the total 55 patients at a median follow-up time of 4.5 years after the first seizure (range 1-17.4 years). Only two variables, a pericavity hyperintense signal on T2-weighted magnetic resonance (MR) images and at least 10 seizures prior to therapy for seizures, were associated with uncontrolled seizures.
CONCLUSIONS: Lesionectomy may be appropriate in children with low-grade brain tumors. A large number of seizures before therapy and a hyperintense area around the tumor cavity on postresection MR images are associated with uncontrolled seizures. Medical therapy and tumor resection will control seizures in the majority of children with low-grade tumors.